In order to increase available interior space of recreational vehicles, e.g., motor homes and trailer homes, slide-out rooms or sections are provided. During transit, these rooms are retracted and stored in the interior of the vehicle or trailer, with the exterior end wall of the slide-out room approximately flush with the adjacent exterior wall of the vehicle or trailer. To use the slide-out room, the vehicle is parked and leveled. The slide-out room is then slid outward from the vehicle, using the slide-out room support system, thereby increasing the interior space of the vehicle.
These slide-out rooms usually include a floor, a roof, an end wall and one or more side walls. In the retracted position, the roof, floor and side walls are typically inside the stationary part of the vehicle, concealed from exterior view, and the room end wall forms a portion of the vehicle side wall. The floor of the slide-out room typically rests on the floor of the stationary part of the vehicle, and may form a portion of the usable interior floor during transit of the vehicle.
In prior art constructions, the floor of the slide-out room is moved generally horizontally to an extended position. Unless the slide-out floor is somehow lowered by approximately the height of its upper surface above the upper surface of the stationary floor, the slide-out floor remains above the fixed floor in the extended position, creating a height differential, or step up, between the stationary floor and the moveable floor. This height differential is undesirable, inconvenient and creates a trip hazard.
Many methods are known in the art that attempt to avoid a height differential between the fixed and slide-out floors. In U.S. Pat. No. 5,090,749 issued on Feb. 25, 1992 to Lee, wheels of a slide out floor inner rail support member settle into recesses thereby lowering the extended slide-out floor to the same level as the fixed floor. Other methods utilize a mechanical linkage to raise and lower the slide-out floor as disclosed, for example, in U.S. Pat. No. 5,577,351 issued on Nov. 26, 1996 to Dewald et al., or require the entire slide-out floor to traverse a ramp thereby lowering the slide-out floor to the desired elevation as disclosed in U.S. Pat. No. 5,620,224 issued on Apr. 15, 1997 to DiBiagio et al. These structures can be unduly complex, high in cost, difficult to manufacture, and heavy.
Typical prior art flush floor slide-out room operating systems require an abrupt change in direction to lower the floor when extending the room, or to raise the floor when retracting. This change in motion increases the peak power required of the operating system since upon retraction, essentially the entire room must be lifted abruptly, and also increases the potential for failure during extension, since the entire floor is abruptly dropped.
One known structure incorporates an angled outer rail that has a substantially parallel telescoping inner rail connected to the slide-out floor. This configuration positions the slide-out floor as it is extended. This structure, however, requires precious space under the slide-out floor to accommodate the angled outer rail. It therefore remains desirable to provide a flat floor arrangement that is simple, economical to manufacture, dependable in use and fits into the available space.